U.S. patent number 4,492,791 [Application Number 06/488,246] was granted by the patent office on 1985-01-08 for process for the preparation of polyaminotriazines.
This patent grant is currently assigned to Ciba-Geigy Corporation. Invention is credited to Ivan Orban, Eduard Troxler.
United States Patent |
4,492,791 |
Orban , et al. |
January 8, 1985 |
Process for the preparation of polyaminotriazines
Abstract
The known reaction of dichlorotriazines of the formula II
##STR1## in which Q is an ether or amino radical, with diamines of
the formula III in which Pip is a radical of the formula ##STR2##
in which R.sup.1 is hydrogen, C.sub.1 -C.sub.12 -alkyl, C.sub.3
-C.sub.8 -alkenyl, C.sub.7 -C.sub.11 -phenylalkyl, C.sub.2 -C.sub.8
-alkanoyl or C.sub.3 -C.sub.5 -alkenoyl and R is a divalent organic
radical leads to undesirable, sparingly soluble by-products. The
formation of these by-products can be suppressed if the reaction is
carried out in a water-immiscible organic solvent with the addition
of an aqueous base--preferably NaOH or KOH--under pressure at
140.degree.-220.degree. C.
Inventors: |
Orban; Ivan (Basel,
CH), Troxler; Eduard (Basel, CH) |
Assignee: |
Ciba-Geigy Corporation
(Ardsley, NY)
|
Family
ID: |
4240359 |
Appl.
No.: |
06/488,246 |
Filed: |
April 25, 1983 |
Foreign Application Priority Data
Current U.S.
Class: |
544/198;
544/209 |
Current CPC
Class: |
C07D
401/14 (20130101); C08K 5/34926 (20130101); C08G
73/0644 (20130101) |
Current International
Class: |
C07D
401/00 (20060101); C07D 401/14 (20060101); C08G
73/00 (20060101); C08G 73/06 (20060101); C08K
5/00 (20060101); C08K 5/3492 (20060101); C07D
401/14 () |
Field of
Search: |
;544/198,209 |
References Cited
[Referenced By]
U.S. Patent Documents
|
|
|
4086204 |
April 1978 |
Cassandrini et al. |
4335242 |
March 1982 |
Wiezer et al. |
4400505 |
August 1983 |
Loffelman et al. |
4409348 |
October 1983 |
Wiezer et al. |
|
Primary Examiner: Ford; John M.
Attorney, Agent or Firm: Hall; Luther A. R.
Claims
What is claimed is:
1. An improved process for the preparation of a compound of formula
I ##STR10## in which n is a number from 2 to 20, Pip is a radical
of the formula ##STR11## in which R.sup.1 is hydrogen, C.sub.1
-C.sub.12 -alkyl, C.sub.3 -C.sub.8 -alkenyl, C.sub.7 -C.sub.11
-phenylalkyl, C.sub.2 -C.sub.8 -alkanoyl or C.sub.3 -C.sub.5
-alkenoyl, R is C.sub.2 -C.sub.12 -alkylene, which can be
interrupted by --O-- or --NR.sup.2 --, in which R.sup.2 is
hydrogen, C.sub.1 -C.sub.12 -alkyl, C.sub.3 -C.sub.12 -alkoxyalkyl,
cycloalkyl, Pip or a divalent cycloaliphatic C.sub.6 -C.sub.15
-radical, and Q is a radical of the formula --OR.sup.3, --NHR.sup.4
or --NR.sup.4 R.sup.5, in which R.sup.3 is C.sub.1 -C.sub.12 alkyl,
C.sub.3 -C.sub.12 -alkoxyalkyl, cyclohexyl, benzyl, phenyl, tolyl
or Pip, R.sup.4 is C.sub.1 -C.sub.12 -alkyl, C.sub.3 -C.sub.12
-alkoxyalkyl, C.sub.4 -C.sub.12 -dialkylaminoalkyl, allyl, benzyl,
cyclohexyl, phenyl, tolyl or Pip and R.sup.5 is C.sub.1 -C.sub.12
-alkyl, C.sub.3 -C.sub.12 -alkoxyalkyl or cyclohexyl, or R.sup.4
and R.sup.5 together with the N atom to which they are bonded form
a 5- or 6-membered heterocyclic ring, by polycondensation of a
dichlorotriazine of the formula II ##STR12## with a diamine of the
formula III
in a molar ratio of 1 mol of dichlorotriazine of formula II to 1.0
to 1.2 moles of diamine of formula III in an inert organic solvent
in the presence of a base wherein the improvement comprises
carrying out the reaction in a water-immiscible organic solvent and
an aqueous solution of an inorganic base at a temperature of
140.degree.-220.degree. C. under elevated pressure.
2. The process according to claim 1 for the preparation of a
compound of the formula I in which R.sup.1 is hydrogen or methyl, R
is a straight-chain or branched C.sub.4 -C.sub.12 -alkylene radical
and Q is a radical --NHR.sup.4.
3. The process according to claim 2 for the preparation of
compounds of the formula I in which R is hexamethylene and R.sup.4
is a C.sub.6 -C.sub.12 -alkyl radical.
4. The process according to claim 1, wherein a concentrated aqueous
solution of sodium hydroxide or potassium hydroxide is used as the
base.
5. The process according to claim 1, wherein the diamine III is
used in an excess of 1-10 mol %.
6. The process according to claim 1, wherein the reaction mixture
is stirred so slowly that no turbulent mixing of the two phases
occurs.
7. The process according to claim 1, wherein the reaction is
carried out at 180.degree.-190.degree. C.
8. The process according to claim 1, wherein the triazine component
of the formula II is slowly added, at the reaction temperature, to
the solution of the diamine of the formula III.
Description
The invention relates to an improved process for the preparation of
polyaminotriazines by polycondensation of dichlorotriazines with
secondary diamines which are substituted on the nitrogen by
2,2,6,6-tetramethylpiperidin-4-yl radicals.
German Offenlegungsschrift No. 2,636,144 discloses compounds of the
formula ##STR3## in which X, Y and Z are --O--, --NH-- or
--NR.sub.3 --, R.sub.1 is a divalent organic radical, R.sub.2 and
R.sub.3 are monovalent radicals and at least one of the radicals
R.sub.2 or R.sub.3 is a polyalkylpiperidine radical, m is zero or
1, n is a number from 2 to 200 and A and B are end groups. Such
compounds are excellent light stabilisers, especially for organic
polymers, and are used industrially for stabilising plastics.
According to German Offenlegungsschrift No. 2,636,144, these
polyaminotriazines are prepared by polycondensation of a
dichlorotriazine of the formula ##STR4## or of a cyanuric halide in
an inert solvent at a temperature of -10.degree. up to the boiling
point of the solvent, in the presence of an organic or inorganic
base.
In the examples, the reaction is chiefly carried out in boiling
toluene, and anhydrous NaOH is used as the base. The mixture is
worked up by filtering off the NaCl formed and evaporating off the
solvent. This process has the disadvantages that the reaction does
not proceed to completion, and that sparingly soluble by-products,
in particular cyclic by-products, are formed. Because these
products are sparingly soluble, they are undesirable as stabilisers
and must be separated off from the linear polycondensate by
filtration. Besides the loss in yield resulting from the formation
of these by-products, there is the disadvantage that the
by-products are very difficult to filter off since they are in a
very finely pulverulent form and thereby block the filter pores.
After these undesirable by-products have been separated off, the
yield in the process given is thus only about 70-75%. A third
disadvantage of the process is that only products having a
relatively low degree of polycondensation n<6 can be obtained. A
low n is generally desirable if the products are used as
stabilisers, but products having a higher molecular weight would be
desirable for particular purposes.
If an excess of NaOH is used to improve the yield of the known
process, an increased amount of insoluble by-products are formed,
and partial hydrolysis of the halogen on the triazine ring occurs,
so that no substantial increase in the yield of linear
polyaminotriazines is achieved.
German Offenlegungsschrift No. 2,933,078 discloses quite similar
polyaminotriazines which are likewise prepared by polycondensation
in boiling toluene or xylene, with addition of anhydrous NaOH. In
this case also, only products of very low molecular weight are
obtained, and the yield is inadequate.
It has now been found that the disadvantages described can largely
be avoided if the reaction is carried out at elevated temperatures
in a two-phase system. For this, a water-immiscible solvent in
which the starting materials and end products are soluble and, as
the base, a concentrated aqueous solution of an inorganic base are
used. The reaction is carried out under pressure, so that elevated
temperatures can be applied.
The invention thus relates to a process for the preparation of
compounds of the formula I ##STR5## in which n is a number from 2
to 20, Pip is a radical of the formula ##STR6## in which R.sup.1 is
hydrogen, C.sub.1 -C.sub.12 -alkyl, C.sub.3 -C.sub.8 -alkenyl,
C.sub.7 -C.sub.11 -phenylalkyl, C.sub.2 -C.sub.8 -alkanoyl or
C.sub.3 -C.sub.5 -alkenoyl, R is C.sub.2 -C.sub.12 -alkylene, which
can be interrupted by --O-- or --NR.sup.2 --, in which R.sup.2 is
hydrogen, C.sub.1 -C.sub.12 -alkyl, C.sub.3 -C.sub.13 -alkoxyalkyl,
cycloalkyl or Pip, or R is a divalent cycloaliphatic C.sub.6
-C.sub.15 -radical, and Q is a radical of the formula --OR.sup.3,
--NHR.sup.4 or --NR.sup.4 R.sup.5, in which R.sup.3 is C.sub.1
-C.sub.12 -alkyl, C.sub.3 -C.sub.12 -alkoxyalkyl, cyclohexyl,
benzyl, phenyl, tolyl or Pip, R.sup.4 is C.sub.1 -C.sub.12 -alkyl,
C.sub.3 -C.sub.12 -alkoxyalkyl, C.sub.4 -C.sub.12
-dialkylaminoalkyl, allyl, benzyl, cyclohexyl, phenyl, tolyl or Pip
and R.sup.5 is C.sub.1 -C.sub.12 -alkyl, C.sub.3 -C.sub.12
-alkoxyalkyl or cyclohexyl, or R.sup.4 and R.sup.5 together with
the N atom to which they are bonded form a 5- or 6-membered
heterocyclic ring, by polycondensation of 1 mol of a
dichlorotriazine of the formula II ##STR7## with 1.00 to 1.20 mols
of a diamine of the formula III
in an inert organic solvent with addition of a base, wherein an
aqueous solution of an inorganic base is used as the base, a
water-immiscible solvent is used, and the reaction is carried out
at 140.degree.-220.degree. C. under pressure.
R can be a straight-chain or branched alkylene radical which may be
interrupted by --O-- or --NR.sup.2 --. Examples of R are
1,2-ethylene, tri-, tetra-, penta-, hexa-, octa-, deca- or
dodeca-methylene, 2,2,4- or 2,4,4-trimethylhexamethylene,
4-oxahept-1,7-ylene, 4,7-dioxadec-1,10-ylene,
4-(methylaza)-hept-1,7-ylene, 4-(cyclohexylaza)-hept-1,7-ylene and
4-(1,2,2,6,6-pentamethyl-4-piperidyl-aza)-hept-1,7-ylene. R can
also be a cycloaliphatic radical, for example 1,3- or
1,4-cyclohexylene, dicyclohexylmethane-4,4'-diyl or a radical of
the formula ##STR8##
An alkyl radical R.sup.1, R.sup.2, R.sup.3, R.sup.4 or R.sup.5 can
be, for example, methyl, ethyl, propyl, isopropyl, n-butyl,
tert.-butyl, isoamyl, n-hexyl, 2-ethylhexyl, n-octyl,
ditert.-octyl, n-decyl or n-dodecyl.
An alkoxyalkyl radical R.sup.3, R.sup.4 or R.sup.5 can be, for
example, 2-methoxyethyl, 2-ethoxyethyl, 3-ethoxypropyl,
3-butoxypropyl or 3-isopropoxypropyl. A dialkylaminoalkyl radical
R.sup.4 can be, for example, 2-dimethylaminoethyl,
3-dimethylaminopropyl, 3-diethylaminopropyl or
3-dibutylaminopropyl.
An alkenyl radical R.sup.1 can be, for example, allyl, methallyl or
dimethylallyl. A phenylalkyl radical R.sup.1 can be, for example,
benzyl, phenethyl or phenylpropyl. An alkanoyl radical R.sup.1 can
be, for example, acetyl, propionyl, butyroyl, hexanoyl or octanoyl.
An alkenoyl radical R.sup.1 can be, for example, acryloyl,
methacryloyl or crotonoyl.
This process permits virtually quantitative conversion and a high
yield of linear polytriazines of the formula I. Not only is the
conversion increased, but also the formation of the sparingly
soluble by-products is suppressed, and these are obtained in a
coarser form in which they can be filtered more easily. A serious
industrial problem is thereby solved.
Moreover, on the basis of the high conversion, it is possible to
obtain products with a high degree of polycondensation n. However,
if products having a low n are required, these can also be obtained
in the present process in a conventional manner by using an
appropriate excess of the diamine III.
A small excess of diamine is advantageous. A 0-20 mol %, preferably
a 2-5 mol %, excess of III is used, depending on the desired
molecular weight or degree of polycondensation. Degrees of
polycondensation n of 2-20, preferably 4-10, are thereby
achieved.
It is surprising that, when an aqueous base is used, the formation
of sparingly soluble by-products is suppressed and the yield is
increased. According to the literature, it was to be expected that
the Cl atoms would be saponified under aqueous/alkaline conditions
in a temperature range above 140.degree. C.
The process can be carried out with a large number of
dichlorotriazines of the formula II and diamines of the formula
III. However, those dichlorotriazines of the formula II in which Q
is a radical --NHR and those diamines of the formula III in which R
is a straight-chain or branched C.sub.4 -C.sub.12 -alkylene radical
and R.sup.1 is hydrogen or methyl are preferably used.
Dichlorotriazines of the formula II in which Q is the radical
--NH--C.sub.6 --C.sub.12 -alkyl and those diamines of the formula
III in which R is hexamethylene and R.sup.1 is hydrogen or methyl
are particularly preferred.
The dichlorotriazines of the formula II can be prepared from
cyanuric trichloride and a monofunctional compound QH, such as is
described in German Offenlegungsschrift No. 2,636,144 or in German
Offenlegungsschrift No. 2,933,078. The reaction solution thereby
obtained can be used for the present process, without the compound
II being isolated. However, the compound II is preferably isolated
before it is further reacted.
The diamines of the formula III can be prepared by hydrogenating
amination of triacetonamine, such as is described in German
Offenlegungsschrift No. 2,611,208.
The organic solvents are, in particular, hydrocarbons, for example
toluene, xylene, mesitylene, tetralin, decalin and higher
alkylbenzenes, for example nonylbenzene and dodecylbenzene and
mixtures of such alkylbenzenes.
The inorganic bases are, in particular, those which are highly
soluble in water, for example alkali metal hydroxides and alkali
metal carbonates. Sodium hydroxide or potassium hydroxide is
preferably used, and the reaction is preferably carried out using
30-60%, in particular about 50%, solutions of the inorganic
base.
The temperatures used are higher than those which have hitherto
been described, and the reaction is preferably carried out at
170.degree.-190.degree. C. A closed vessel is used, so that
increased pressure results from the vapour pressures of the solvent
and of the water prevailing at the reaction temperature. This
increased pressure is about 0.5-1 MPa, so that it is not necessary
to carry out the reaction in a thick-walled autoclave. The reaction
is preferably carried out in a pressure-resistant stirred kettle.
Stirring should not be intensive, and turbulent mixing of the two
phases is to be avoided. The use of an anchor-type stirrer at a
speed of 40-45 rpm is to be recommended.
Preferably, all of the solution of the diamine of the formula III
and of the base are taken, the solution is warmed to the desired
reaction temperature and the solution of the triazine component of
the formula II is slowly metered in, with stirring. It is also
possible however to take all the reaction components, and to heat
the mixture to the desired reaction temperature. The degree of
polycondensation n becomes in this case somewhat lower.
When the reaction has ended, the aqueous phase is separated off,
the organic phase is dried--preferably by azeotropic
distillation--and the solution is filtered. Filtration can be
accelerated by addition of a filtration auxiliary, for example
kieselguhr or fuller's earth. After the solvent has been evaporated
off, the polyaminotriazine remains as a mass which is solid at room
temperature and which can be comminuted as required .
The examples which follow illustrate the process in more detail,
without restricting it to the procedure of the examples.
EXAMPLE 1 ##STR9##
413.7 g (1.05 mols) of
N,N'-bis-(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine and
175 g of 50% aqueous sodium hydroxide solution are introduced into
a 2.5 l low-pressure autoclave at 180.degree. C. A solution of
276.5 g (1.0 mol) of tert.-octylamino-dichloro-s-triazine (prepared
from cyanuric chloride and tert.-octylamine) in 450 g of xylene is
metered into the mixture, with stirring, as follows: 85% of the
xylene solution within 3 hours, and then the remaining 15% within 4
hours. A maximum pressure of 0.7 MPa is established. After the
reaction mixture has been kept for another 5 hours at 185.degree.
C., it is cooled to 80.degree.-90.degree. C. and washed once with
water. After the aqueous phase has been separated off, the xylene
phase is dehydrated azeotropically and, after addition of the
filtration auxiliary Celite 545, is filtered. The clear filtrate is
evaporated at 200.degree. C. in a rotary evaporator, the melt which
remains is cooled and the resulting solid resin is comminuted.
Yield: 573.5 g=93% of theory.
A mean molecular weight M.sub.n (number-average) of 4,900 was found
by gel permeation analysis and vapour pressure osmometry. This
corresponds to a degree of polycondensation n of 7.5.
EXAMPLE 2
403.8 g (1.025 mols) of
N,N'-bis-(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine are
reacted with the amounts of dichlorotriazine and sodium hydroxide
solution given in Example 1 by a method similar to that described
in Example 1. The same working up conditions give 583 g=96% of
theory. M.sub.n =6,300, corresponding to n=9.9.
EXAMPLE 3
The procedure described in Example 1 is repeated, except that 423.6
g (1.075 mols) of the diamine are used.
Yield: 5,914 g=94.3% of theory. M.sub.n =3,660, corresponding to
n=5.5.
* * * * *